Matt,
I have finally taken some photos of the part in question. It is currently in an ackward location under some stuff in my other shed, so I wasn't able to get photos from directly above. Hope these two are good enough.
As you can see, two of the propellor blades have been snapped off at the blade root, leaving traces of blade as shown. The third one is completely gone. My guess is that the gap between blade remnants and central hub of the three blades is where the variable pitch mechanism would have been. There is evidence of this on one of the blade sides, but it is not visible in these photos.
As a reference to size, the object on left of photos is a motor mower catcher. The piece is sufficiently heavy that I can only lift it for a second or two. Two person lifting is not much better either. It took me several lift attempts to heave it up to my car boot. Was just as much fun getting it out too!
As indicated, this was given to me some years ago, and advised to be from a Boeing B-17 that crashed. I can virtually guarantee it isn't from a Cessna.
My plan is to incorporate this artifact in a memorial to WWII airmen. Especially those airmen that did not return.
